Agricultural tools or blades called sweeps are generally mounted on downward depending shanks or tines of an agricultural implement pulled along the ground by an agricultural tractor or the like so that the sweeps are pulled through the soil to till the ground by cutting off or uprooting undesirable plants, sowing seeds breaking up the soil, etc. A typical agricultural sweep includes an earth or ground engaging body portion having an arrowhead or triangular-like shape forming a point or nose at the forward end with two symmetrical wing-like bodies sweeping rearward therefrom to define cutting edges at the leading edges of the wings on either side of the point. A stem or mounting portion typically extends upward from the body portion for connection to the shank or tine of the implement on which it is installed.
In addition to use of such sweeps in isolation to carry out purely tilling operations, it is known to use sweeps as part of an opener assembly of an air seeder or drill to carry out the tilling or weed kill function of the sweep while simultaneously delivering seed and/or fertilizer, rearward of the sweep. In such arrangements, the sweep not only cuts through weeds but also forms a furrow in the ground having a firm bottom defining a seed bed beneath the ground surface onto which the seed, fertilizer or other product is to be delivered.
It is known in the prior art to equip a sweep opener with a spreader positioned proximate the outlet of the delivery boot in order to widen the spread of seed or fertilizer across the furrow it is being delivered into, thereby taking advantage of the wider furrow provided by the sweep relative to a more narrow furrow-forming tool, such as a knife opener. An exemplary situation where such a wider seed band is useful is the context of a seeding implement where fertilizer and seed are delivered by separate opener groups positioned on group ahead of the other and the spacing between the seed openers across the machine is different from the spacing between the fertilizer openers across the machine, resulting in seed rows and fertilizer rows coinciding and thus leading to seed burn. For example, in a type of seeding and fertilizing machine used in Russia, where fertilizer sweeps are positioned forward of a dual disc box seeder having of different opener spacing, use of spreader-equipped fertilizer openers would decrease seed burn by reducing the concentration of fertilizer at any one point by spreading each fertilizer row over a greater width.
However, in prior art sweep-style openers, the delivery boot through which the product is delivered into the soil typically trails behind the shank that carries the sweep on the opener or drill implement. As a result, the tendency of the soil displaced by pulling of the opener through the ground to fall back into the so-formed furrow as the shank passes by may have a detrimental effect on consistent placement of the seed or fertilizer product, as the soil falling back into the newly formed furrow may obstruct or interfere with delivery of the product to the seed or fertilizer bed defined at the furrow bottom. Consistent seed and fertilizer placement promotes improved and more consistent crop germination, emergence and yield.